Growth and Characterization of Heteroepitaxial Layers of GeSiSn Ternary Alloy

Abstract

We have examined the epitaxial growth of Ge1-x-ySixSny layers on Ge substrates with a Sn content of 3~15% with low temperature molecular beam epitaxy method. The Ge1-x-ySixSny layers are psuedomorphically grown on Ge substrates with high crystalline quality. The surface morphology of the Ge1-x-ySixSny layers with a Sn content below 7% shows very flat and uniform, although surface roughening occurs in the sample with a Sn content as high as 15% provably due to the Sn precipitation. We also roughly estimated the energy band structure with liner approximation calculation. The energy bandgap of Ge1-x-ySixSny alloy prepared in this study is expected to be 0.8~1.0 eV at the L or X point.

Growth and applications of GeSn-related group-IV semiconductor materials

“…The crystal growth of Ge 1− x − y Si x Sn y ternary alloy thin films with MBE [80, 81] and CVD [46, 75] methods has been reported. Recently, we reported the epitaxial growth of Ge 1− x − y Si x Sn y layers whose lattice matches that of a Ge(001) substrate using the MBE method [81, 82].…”

“…Recently, we reported the epitaxial growth of Ge 1− x − y Si x Sn y layers whose lattice matches that of a Ge(001) substrate using the MBE method [81, 82]. The crystalline structure of lattice-matching Ge 1− x − y Si x Sn y epitaxial layers on Ge is often superior to that of strained Ge 1− x Sn x layers on Ge substrates because the effect of strain is minimized.…”

Growth and applications of GeSn-related group-IV semiconductor materials

“…The crystal growth of Ge 1−x−y Si x Sn y ternary alloy thin films with MBE [80,81] and CVD [46,75] methods has been reported. Recently, we reported the epitaxial growth of Ge 1−x−y Si x Sn y layers whose lattice matches that of a Ge(001) substrate using the MBE method [81,82].…”

“…A Ge 1−x−y Si x Sn y epitaxial layer whose lattice matches that of a Ge substrate with an energy bandgap of 1.0 eV is suitable for use as the buffer layer for an In 1−x Ga x As layer. [173] Recently, we also proposed a multijunction cell with all group-IV semiconductor alloys, including Ge 1−x−y Si x Sn y , Ge 1−x−y C x Sn y , and Si 1−x−y Sn x C y [81,[86][87][88]. We investigated the solar cell actions of Ge 1−x−y Si x Sn y /Ge heterojunction structures and observed the enhancement of the external quantum efficiency at an energy of 1.0 eV, corresponding to the energy bandgap of the Ge 1−x−y Si x Sn y epitaxial layer [174,175].…”

Effect of Sn on crystallinity and electronic property of low temperature grown polycrystalline-Si1−−Ge Sn layers on SiO2

“…Moreover, Si 1ÀxÀy Ge x Sn y is an attractive material for optoelectronic applications such as solar cell and quantum well laser [12][13][14]. On the other hand, a problem is Sn precipitation from the polycrystalline layer during the polycrystallization of Si 1ÀxÀy Ge x Sn y due to the low thermo-equilibrium solid solubility limit of Sn in Si or Ge, (0.1 at.% in bulk Si, and 1.0 at.% in bulk Ge) [15,16].…”